How to use Visual Builder to generate/import SmartGWT java code?

Hello,

I have tested Visual Builder in SmartGWT 4.1p Eval Edition 2014-Mar-21 build

And I want to know how can I,
1. to import the existing SmartGWT client java implementation (such as a VLayout with DynamicForm...) into the Visual Builder?
2. and how to generate SmartGWT client java code after I draw the components in the Visual Builder? I can only found that it can export by xml and js but no java...
3. Or some convert that I can convert the XML/JS code to java code so that I can proceed the java implementation?


Best Regards